CLINICAL ANATOMY

CLINICAL ANATOMY

The normal cervical lordosis measures between 35° and 45°. The normal lumbar lordosis is between 40° and 80° (mean 60°) and decreases with age. Most lumbar lordosis occurs between L4 and S1. The normal thoracic kyphosis is between 20° and 50° (mean 35°) and increases with age. When standing, the normal sagittal vertical axis (sagittal plumb line) falls from the odontoid process through the C7/T1 disc space and crosses the spinal column at the T12/L1 disc space, before reaching the posterosuperior corner of the S1 vertebral body . For an energy-e ffi cient posture, cervical and lumbar lordosis will balance thoracic kyphosis. The spinal canal is formed behind the articulated vertebral body by the posterior elements of the vertebral column and can Albert Adamkiewicz , 1850–1921, Professor of Pathology , the University of Kraków (Cracow), Poland, described the arterial supply to the spinal cord in 1882. be divided into a central portion and two lateral portions. The central portion is occupied by the thecal sac containing the spinal cord, which terminates behind the body of L1. The lateral portions contain the nerve roots. The spinal nerve roots comprise 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal. Dorsal and ventral roots join to form spinal nerves. The ventral root and the dorsal root gang lion lie within the intervertebral foramen. This fora - men is bounded superiorly and inferiorly by pedicles, anteri - orly by the disc and posteriorly by the facet joint. Degenerative changes in these structures may lead to neural compromise. Laminar overlap within the lumbar spine decreases from L1 to S1 so that, at the L5/S1 level, access to the intervertebral disc requir es less bone removal than at a more proximal level. The blood supply of the spinal cord is derived from the vertebral, deep cervical, intercostal and lumbar arteries. The arteries of the spinal cord include the anterior spinal artery and two posterior spinal arteries, with the anterior spinal artery providing the majority of the vascular supply to the spinal cord. The radicular artery of Adamkiewicz makes a major contribution to the anterior spinal artery , supplying the lower spinal cord. It originates on the left in 80% of people, usually accompanying the ventral root of T9, T10 or T11, but can originate anywhere from T5 to L5. Ligation of this important artery may lead to critical ischaemia of the spinal cord. Ligat - ing segmental vessels over the midpoint of the vertebral body will minimise the risk of injury to this important artery during anterior approaches to the spine.

The treatment principles for common conditions affecting • the spine The global issues in spinal surgery •

CLINICAL ANATOMY

The normal cervical lordosis measures between 35° and 45°. The normal lumbar lordosis is between 40° and 80° (mean 60°) and decreases with age. Most lumbar lordosis occurs between L4 and S1. The normal thoracic kyphosis is between 20° and 50° (mean 35°) and increases with age. When standing, the normal sagittal vertical axis (sagittal plumb line) falls from the odontoid process through the C7/T1 disc space and crosses the spinal column at the T12/L1 disc space, before reaching the posterosuperior corner of the S1 vertebral body . For an energy-e ffi cient posture, cervical and lumbar lordosis will balance thoracic kyphosis. The spinal canal is formed behind the articulated vertebral body by the posterior elements of the vertebral column and can Albert Adamkiewicz , 1850–1921, Professor of Pathology , the University of Kraków (Cracow), Poland, described the arterial supply to the spinal cord in 1882. be divided into a central portion and two lateral portions. The central portion is occupied by the thecal sac containing the spinal cord, which terminates behind the body of L1. The lateral portions contain the nerve roots. The spinal nerve roots comprise 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal. Dorsal and ventral roots join to form spinal nerves. The ventral root and the dorsal root gang lion lie within the intervertebral foramen. This fora - men is bounded superiorly and inferiorly by pedicles, anteri - orly by the disc and posteriorly by the facet joint. Degenerative changes in these structures may lead to neural compromise. Laminar overlap within the lumbar spine decreases from L1 to S1 so that, at the L5/S1 level, access to the intervertebral disc requir es less bone removal than at a more proximal level. The blood supply of the spinal cord is derived from the vertebral, deep cervical, intercostal and lumbar arteries. The arteries of the spinal cord include the anterior spinal artery and two posterior spinal arteries, with the anterior spinal artery providing the majority of the vascular supply to the spinal cord. The radicular artery of Adamkiewicz makes a major contribution to the anterior spinal artery , supplying the lower spinal cord. It originates on the left in 80% of people, usually accompanying the ventral root of T9, T10 or T11, but can originate anywhere from T5 to L5. Ligation of this important artery may lead to critical ischaemia of the spinal cord. Ligat - ing segmental vessels over the midpoint of the vertebral body will minimise the risk of injury to this important artery during anterior approaches to the spine.

The treatment principles for common conditions affecting • the spine The global issues in spinal surgery •

CLINICAL ANATOMY

The normal cervical lordosis measures between 35° and 45°. The normal lumbar lordosis is between 40° and 80° (mean 60°) and decreases with age. Most lumbar lordosis occurs between L4 and S1. The normal thoracic kyphosis is between 20° and 50° (mean 35°) and increases with age. When standing, the normal sagittal vertical axis (sagittal plumb line) falls from the odontoid process through the C7/T1 disc space and crosses the spinal column at the T12/L1 disc space, before reaching the posterosuperior corner of the S1 vertebral body . For an energy-e ffi cient posture, cervical and lumbar lordosis will balance thoracic kyphosis. The spinal canal is formed behind the articulated vertebral body by the posterior elements of the vertebral column and can Albert Adamkiewicz , 1850–1921, Professor of Pathology , the University of Kraków (Cracow), Poland, described the arterial supply to the spinal cord in 1882. be divided into a central portion and two lateral portions. The central portion is occupied by the thecal sac containing the spinal cord, which terminates behind the body of L1. The lateral portions contain the nerve roots. The spinal nerve roots comprise 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal. Dorsal and ventral roots join to form spinal nerves. The ventral root and the dorsal root gang lion lie within the intervertebral foramen. This fora - men is bounded superiorly and inferiorly by pedicles, anteri - orly by the disc and posteriorly by the facet joint. Degenerative changes in these structures may lead to neural compromise. Laminar overlap within the lumbar spine decreases from L1 to S1 so that, at the L5/S1 level, access to the intervertebral disc requir es less bone removal than at a more proximal level. The blood supply of the spinal cord is derived from the vertebral, deep cervical, intercostal and lumbar arteries. The arteries of the spinal cord include the anterior spinal artery and two posterior spinal arteries, with the anterior spinal artery providing the majority of the vascular supply to the spinal cord. The radicular artery of Adamkiewicz makes a major contribution to the anterior spinal artery , supplying the lower spinal cord. It originates on the left in 80% of people, usually accompanying the ventral root of T9, T10 or T11, but can originate anywhere from T5 to L5. Ligation of this important artery may lead to critical ischaemia of the spinal cord. Ligat - ing segmental vessels over the midpoint of the vertebral body will minimise the risk of injury to this important artery during anterior approaches to the spine.

The treatment principles for common conditions affecting • the spine The global issues in spinal surgery •